1. Field of the Invention
The present invention relates to a form measuring instrument.
2. Description of Related Art
A known form measuring instrument includes a probe that is movable within a predetermined range and is provided with a stylus tip designed to contact with an object, the stylus tip being brought into contact with the object to measure a profile of the object (see, for instance, Patent Literature 1: JP-T-2004-521343, Patent Literature 2: JP-A-5-87501 and Patent Literature 3: JP-A-6-201366).
A coordinates measuring machine (form measuring instrument) disclosed in Patent Literature 1 uses a probe calibration matrix for associating the position of the probe with a coordinate system of the coordinates measuring machine.
Coordinate measuring machines disclosed in Patent Literatures 2 and 3 perform compensation based on Hertzian elastic contact theory and a measuring force ratio to calculate a measurement value.
However, a form measuring instrument that uses an image represented by a matrix to calculate a measurement value (e.g., the coordinates measuring machine disclosed in Patent Literature 1) and a form measuring instrument that performs compensation based on a measuring force ratio to calculate a measurement value (e.g., the coordinates measuring machine disclosed in Patent Literature 2 or 3) do not take motion characteristics of a probe into consideration, so that these form measuring instruments cannot compensate a measurement error based on the motion history of the probe, such as a phase delay due to the motion characteristics of the probe.